The invention relates to a method for mounting an angle measuring device with a stator and a rotor on an electronic motor with a stator and a rotor. The invention also relates to a unit comprising an electric motor and an angle measuring device fastened thereto.
The task of the angle measuring device, which is also referred to as a rotary transducer, is to measure the relative position of the rotor of the motor with respect to the stator of the motor. For this purpose, the rotor of the angle measuring device is connected to the rotor of the motor, and the stator of the angle measuring device is connected to the stator of the motor. If in this case the relative relationship between the two rotors is known, the angle measuring device merely needs to measure the relative position between its own rotor and its own stator in order to be able to draw a conclusion regarding the relative position between the rotor of the motor and the stator of the motor. However, the problem consists precisely in the fact that the relative relationship between the two rotors needs to be known: in general a clutch comprising two clutch halves which can be connected to one another in any desired relative positions with respect to one another is used for connecting the rotors. Generally, the clutch half on the motor rotor has an inner cone, and the clutch half on the rotor of the angle measuring device has an outer cone. The outer cone precisely matches the inner cone. The inner cone and the outer cone are rotationally symmetrical with respect to rotations through any desired angle of between 0° and 360°. As a result of the clutch, a relative position of the two rotors with respect to one another is therefore not predetermined. In order to achieve a defined relative position of the two rotors in the prior art with respect to one another, the rotor of the angle measuring device is brought into a predetermined initial position with respect to the stator of the angle measuring device. The rotor of the motor then also needs to be brought into a defined position with respect to the stator of the motor, to be precise by suitable energization of the motor with predetermined signals. Then, the two clutch halves need to be connected to one another accurately. It is particularly disruptive that the adjustment of the two rotors and therefore of the two clutch halves with respect to one another needs to take place each time if the angle measuring device is separated from the motor. This may be required in the course of maintenance, and this maintenance is even made more difficult by the fact that the motor needs to be energized with predetermined signals each time in order that the rotor of the motor assumes a predetermined relative position with respect to the stator of the motor.